Ed excel Chemistry A2 12th June, Wednesday

hey! how u doing? feeling prepared for this unit?

Also did I need to remember persulfate ?

A possibility But I thought maybe you could look in the data booklet, and I think you can look at the dissociation constants & compared.... that's if your really stuck I think it'll be obvious from there but I've never tried it.

& I'm not sure if your right Steamy fumes is for HCl... but I think NH4Cl is white "smoke"

And yes please I will be going to sleep by 12 though I am worrying too much... I hope I get sleep

Explain to me in terms of kinetic/heat energy.... why exothermic reactions have positive entropy surroundings and also usually negative entropy of systems

Not sitting it :P
Will be doing Chemistry Unit 5 next Wednesday though!
I came to wish you all good luck as Unit 4 is my favourite Unit, but I think I'm unpopular in this opinion

oh yeah! u did stay excess ammonia! so yeah white smoke
no u dont have to remember about persulphate but there are others too even haber process and contact process are example of heterogenous catalyst

they give off heat so increase in kinetic energy of molecules in air increase in disorder not sure about the system
how can u distinguish between CHO and RCOR? give both tests

that's a relief !!!

Hehe, well if kinetic/heat energy being lost by the system then I'm sure molecules will behave themselves more and become more ordered

Hmmmmm Aldehyde will give silver mirror with tollens reagant & Red precipitate with Fehlings

+ you can use brady's reagant

(before you say I'm wrong... you then filter off the precipitate add minimum hot ethanol then leave it recrystallize Then check melting temp)

Explain to me how Iodine clock works !

lucky you! what did u get?

Please tell me how is the ans C?
Its june 2011 q6

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A middle B :P
Not really bothered, as I retook Unit 1 and have good A2 practicals.
Goodluck with this! Not sure that you'll need it though :P

lol finally u got the tests name right!
u mix the reactant and record time taken to make specific amount of product

why is acyl chloride more reactive than amide for addition elimination rxn?

Please tell me how is the ans C?
Its june 2011 q6

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We don't need to know which reagents you pit in... like peroxide KI starch..?

Erm I never knew amides underwent addition elimination & electroneg Cl- + oxygen are pulling electrons away from carbon.. this makes it very delta +. Also Cl- is a very good leaving group & The C-Cl bond is very weak

ketone + LiAlH4 ... describe the process

Love Unit 4!
You guys will be great

lol hopefully we dont and yeah ur answer is right
dont think we need to know the process though

There's so much we don't need to know lol (Damn george )

I have far less time this time for unit 5.... so I might abandon george and just use revision guides..

Well anyway I am off to get some sleep now

Good luck AS01 with your exam tomorrow... & speak to ya soon Thanks for all the questions also you've asked me (I have learnt a lot, imagine brady's came up tomorrow )

And good luck to everyone else too who reads this ! May speak to some of you tomorrow morning

im in sri lanka.. i got 3 more hours till the exam.. :P anybody here? wanna revise sum stuff? :P

What time is your exam? Our exam starts at 5.. I'm tempted to ask you what will pop up in the exam now haha

ooops.. i got the time wrong. its at 5.30pm local time. i was thinking 1.30.!!!.
so i got 6 hours i guess

Oh lol then we have it at the same time almost

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